1. Field of the Invention
The present invention relates to a solid electrolytic capacitor, an electronic component module including a solid electrolytic capacitor, a method for producing a solid electrolytic capacitor, and a method for producing an electronic component module. Particularly, the present invention relates to an anode lead terminal of a solid electrolyte capacitor.
2. Description of the Related Art
As shown in FIG. 9, a known solid electrolytic capacitor 1 includes: a plurality of capacitor elements 110 each having a dielectric material section 111, an anode section 112 and a cathode section 113; an anode lead terminal 118 connected to the anode section 112; a cathode lead terminal 119 connected to the cathode section 113; and an exterior resin 116 covering the plurality of capacitor elements 110. As the anode lead terminal 118 and the cathode lead terminal 119, articles obtained by applying Sn-platings 118c and 119c to base materials 118a and 119a formed of a Fe—Ni-based alloy or a Cu-based alloy are used.
However, in reflow soldering, the operation temperature of which is 235° C. to 260° C., the problem occurs that Sn-platings 118c and 119c of the anode lead terminal 118 and the cathode lead terminal 119 are melted to generate gaps between the lead terminals and the exterior resin 116, so that air tightness is impaired. As a countermeasure thereto, it is conceivable that as a plating material, a high-melting-point metal (melting point: 400° C. or higher) such as, for example, Ni (melting point: 1450° C.) or Au (melting point: 1064° C.) is used rather than using a low-melting-point metal such as Sn (melting point: 232° C.)
Japanese Patent Laid-open Publication No. 2003-124074 describes that for reducing a region of a plating layer with a high-melting-point metal, an Au-plating layer is formed on only one surface of the anode lead terminal 118, and the anode section 112 of the capacitor element 110 is resistance-welded to the Au-plating layer.
However, in combination of Au that is a material of an Au-plating layer formed on the anode lead terminal 118 and aluminum that is a material of the anode section 112 of the capacitor element 110, the electric resistance during resistance welding is too low to generate heat, so that it is difficult to bond the anode lead terminal 118 and the capacitor element 110 to each other.